1. Field of the Invention
The present invention relates to an image pickup apparatus, and more particularly to an image pickup apparatus which has a dustproof function and is of an image pickup lens interchangeable type.
2. Description of the Related Art
Conventionally, image pickup apparatuses such as a digital camera and a video camera (hereinafter, generically called cameras) have been generally commercialized and widely used, which sequentially convert optical images formed by photographing optical systems into image signals by photoelectric conversion elements and the like (hereinafter, simply called image pickup devices and the like) such as solid-state image pickup devices, can record the image signals obtained thereby in recording media as image data in a predetermined mode, and are configured by including image display apparatuses such as liquid crystal display apparatuses (LCD) which reproduce and display the image data recorded in the recording media as images.
Further, in this kind of camera, a so-called taking lens interchangeable camera has been commercialized for a long time, which is configured such that the taking lens unit including a photographing optical system is configured to be attachable to and detachable from a camera main body, and is enabled to be used by being replaced with a taking lens unit having a desired kind (angle of view or the like) of photographing optical system in accordance with necessity.
A taking lens interchangeable type camera of such a mode has a high possibility that microscopic dust particles and the like adhere to a light receiving surface of, for example, an image pickup device or the like, or the surface of an optical element and the like which are provided at a front surface side of the image pickup device and the like when the taking lens unit is dismounted from the camera main body. If the use of the camera is continued while dust particles and the like are in the state adhering to the above described light receiving surface or the surface of the optical element, there arises the possibility that, for example, a light incident on the inside of the camera main body through the taking lens is blocked by the above described dust particles and the like. In this case, a pixel portion of the image pickup device or the like corresponding to the spot where the dust particles and the like adhere cannot normally receive an incident light. Accordingly, this causes a problem that a correct image signal cannot be outputted, a dot and the like such as a black point or a stain are formed, and image quality is degraded.
Thus, in the conventional cameras, various contrivances for inhibiting dust particles and the like from adhering to the light receiving surfaces of an image pickup device and the like or the surfaces of an optical element and the like which are provided at the front surface side of the image pickup device and the like are disclosed by, for example, Japanese Patent Application Laid-Open Publication No. 2002-090842, Japanese Patent Application Laid-Open Publication No. 2002-204379, Japanese Patent Application Laid-Open Publication No. 2003-348397 and the like, and are commercialized.
The camera disclosed in the above described Japanese Patent Application Laid-Open Publication No. 2002-090842 is the one in which a protective glass is disposed at a front surface side (lens side, a site near a subject) before a shutter curtain, and a space between the protective glass and the front surface of the image pickup device or the like is formed to be of a sealed structure, whereby disposition is achieved, which inhibits dust particles and the like from adhering to the light receiving surface of the image pickup device and the like, or the optical element at the front surface side of the image pickup device or the like, and enables easy cleaning of the dust particles and the like adhering to the outer surface of the protective glass.
Further, the cameras disclosed in the above described Japanese Patent Application Laid-Open Publication No. 2002-204379 and Japanese Patent Application Laid-Open Publication No. 2003-348397 are the ones in which the optical elements are disposed at the front surfaces of the image pickup devices, the spaces between the optical elements and the image pickup device front surface are formed to be of sealed structures, and vibration applying apparatuses which vibrate the above described optical elements by using vibration applying members are included, whereby the dust particles and the like which adhere to the surfaces of the optical elements are positively removed.